Electric switch



lJune 24, 1941. B. E. GETCHELL ELECTRIC SWITCH 6, 1940 2 Sheets-Sheet lFiled Dec.

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"lilllml .June 24, 1941. B. E. GETCHELI.

ELECTRIC SWITCH 6, 1940 2 Sheets-Sheet 2 Filed Dep.

Patented June 24, 1941 ELECTRIC swrrcn Benjamin a. Gesehen, mamme,conn., signor tov The Trumbull Electric Manufacturing Company,Plainville, Conn., a corporation of Connecticut Application December 6,19M), Serial No. 368,822

(Cl. 20o-50) l Claims. This invention relates generally to enclosed`electric switches and more particularly to front operated switches.

Such switches may be of the single throw, double throw or reversingswitch type andthe form shown is for a three-wire system and has twosets of switch units, each unit having a pair of stationary 'contactsand a connecting movable switch member, all mounted on the front of abase member. Each set of switch units has an operating crank shaft atthe rear of the base and an actuating rocker member is located at oneside of the base and adapted to operate selectively the crank vshai'tsby movement in one direction or another. A lever on the inside ofthe boxoperated by an external handle is adapted to interlock with the rockermember for moving the latter and locking the cover. A separate spring isprovided for biasing each crank shaft.

It is an object of my invention to provide switch actuating mechanismwhich` is positive in moving the operated parts of the switch,

Another object is to prevent closing of the switch cover unless theswitch handle and operatingparts are in proper position. I

Another object is to prevent opening of the switch cover when the switchis in on" position.

Another object is to accelerate the breaking action of the switch. l

Fig. 1 is a front view of an enclosed switch embodying my invention, thehandle being shown in the off or open circuit position and parts of 'theinterior mechanism shown dotted.

Fig. 2 is a vertical sectional view of the casing and showing the switchmechanism in side view, in the open circuit position. g

Fig. 3 is a view similar to Fig. 2 but with one set of parts in theclosed circuit position.

Fig. 4 is an end view partially broken away and showing the parts in theopen circuit position.

Fig. 5 is an inside front view with the cover open and parts shown insection.

Fig. 6 is a detail view showing the throwing' throw, double throw orreversing type. The form shown is of the latter type.

'Ihe insulating body of the switch which carries the contacts, and thequick break mechanism are mounted on a plate Il which is detachablysecured to the bottom of the box by screws I6 and I1. A

'I'he number of circuits controlled by the switch as shown is three butthis is immaterial to the invention, and the switch contacts may be ofthe type shown in Hammerly Patent 1,889,515.

In the form shown there are two crank shafts I8 and I8', each havingbearings I8 and I 9' carried by the plate I8 on opposite sides.

Each switch unit has a pair oi stationary contacts 20 and 2i betweenwhich an insulating carrier bar 22 is movable. This bar has a slottedprojection 22 connected to a crank shaft I8 and carries a switch contactmember 24 which is normally held in the open circuit position by theaction of the spring 2B on the throwing rod 26. This rod has a slottedend 21 which engages a crank shai't I8 and the spring normally holds thecrank shaft and the carrier in the off position where the inner end ofthe carrier 22 or the proiection 23 is pressed against the bottom plateI8 or some other nxed part of the device as shown in Fig. 2.

The end of the rod '26 opposite the slotted part 21 is guided in anaperture 28 in the support 28 so that the rod in eiIect is hinged andslides at one end. The spring 2i bears between the end 21 of the rod anda surface on the support 29.

In the form shown, the upper and lower parts of the device are alikeexcept that the connections are inverted. Between the two parts and atone side of the box is a rocker plate pivoted at 8| to a bracket onplate l5. Two links 32 and 32 are hinged to this rocker plate and haveslotted connections with the crank shafts I8 and i8', respectively,which connections normally hold the rocker plate in the central or offpositions of Fig. 2.

'I'he operating handle or lever 35 is pivoted in the cover plate andnormally hangs in the central position of Fig. 2 when the circuit isopen. The lever 36 is hinged at l1 inside of the cover and has a slotand pin connection 38 with the hub 39 of the handle on the inside of'the cover so that when the handle is moved from side to side the lever36 is swung up and down. The outer end ill of the lever it is shaped andpositioned to enter the notch II of the rocker plate 3i) when the parteare all in the open circuit or oif position.

To close the circuit, it is merely necessary to swing the handle 35 tothe right or left whereupon the lever 36 is moved up or down and therocker plate 30 turned on its axis so as to pull outwardly on one of thelinks 32 or 32 and thus turn a crank shaft, compress a spring, move acarrier and its contact and thus close the circuit, for instance asshown in Fig. 3.

'I'his places the spring 25 under compression slightly beyond center asshown in Figures 3 and 6, which is suillcient to hold this switch lnclosed circuit position. When the parts are thus'positloned, it will beseen thatthe tip 40 of the lever 36 is in back of a hook-like part 42`atone side of the notch 4I in the rocker so that the cover cannot beopened without returning the rocker plate to the "OiT position. Thisserves as a safety interlock of a very simple character.

It will be seen that when the parts are moved to actuate one of theswitches, the other switch is not actuated because the crank shaft isnot affected. This isdue to the slotted connection of its link, and tothe fact that the outer end of the link moves on an arc, a tangent ofsome point of which is substantially perpendicular to the line joiningthe pivot of the rocker plate and the inner end of the link. 'I'herelation of parts for best results is shown in Figure 7 where it will benoted that the slot is made long enough to prevent moving of the yokewhen the switch is operated through this inactive position. Obviously,the slotted connection might be made at the rocker plate end of the linkinstead of at the yoke end, lf desired.

When the handle and rocker plate are turned to ctuate the yoke andswitch,movement of the outerA end of the link is on an arc of the samelength as before, but this arc begins and ends at points such that asubstantially straight pull outward is obtained on the inner end of thelink in a direction toward a tangent to both the arc of movement oftheyoke and the arc of movement of the link pivot on the rocker plate.

It will be seen that the construction of the lever 36 and the rockerprevents the closingv of the cover until the switch is o i and thehandle is in its central position. Likewise the cover cannot be openedwith the circuit on.

Iclaim:

l. .An enclosed switch including a box having a cover hinged at oneedge, switching means in the box including an element pivoted adjacentthe side of the box opposite the hinge of -the cover and having aninterlocking notch opening toward the front of the box, a lever hingedtothe inside of the cover adjacent the hinge of the cover and having itsopposite end adapted to interlock with the notch in said pivotedelement, an operating crank member pivoted to the inside of the coverand having a hinged connection with said lever and an external handle onthe front of the cover and constituting a part of the operating crankmember.

2. In an electric switch, two spring pressed switch units, a rockingmember pivoted at one side, a link connecting each switch unit with saidrocking member, said rocking member having an undercut notch in oneedge, and an actuating lever hinged at one end and having its oppositeend adapted to interlock with the notch in said rocking member.

3. An enclosed switch including a box having a hinged cover, a switchunit in the box having a rocking piece with a slot in one edge thereof ashoulder formed on a wall of said slot and an actuating lever carried bythe cover for' rocking said piece, a portion of said lever being adaptedto interlock with the shoulder upon partial rocking of the piece whenthe cover is closed.

4. A front operated enclosed switch including a box having a hingedcover, a movable handle K on the front of the cover, an actuating leveron the inside of said cover having one end connected to said handle andhaving an inwardly depending lug on its free endh a switch unit in thebox having a rocking plate with -a slot in the edge thereof positionedin the path of the lug of said lever upon closing movement 'of the cover`.and adapted to receive said lug upon closure of the cover and ashoulder on a wall of said slot adapted to be interlocked with the lugon the lever uponl rocking of said plate by the lever when the cover isclosed.

5. An enclosed switch including a box, a cover therefor, an operatinghandle on the front ofthe cover, a lever on the inside of said coverhaving one end connected to said handle, two switch units in the box,each unit including movable switch members and a yoke for actuating saidmovable switch members, and a rocking plate having a slot in its edgenormally positioned centrally of said switch units and when in suchposition adapted to receive the free end of said lever when the cover isclosed for actuating the plate, a separate lost motion link connectionbetween said plate and said yokes whereby movement of the plate isimparted to eitherof said yokes and its respective movable switchmembers to on position, the other yoke remaining stationary, and ashoulder Aon a wail of the slot of said plate' adapted to interlock withthe free end of saidlever when said plate is moved to either side of itscenter to prevent opening of the cover.

6. An enclosed switch including a box, a cover therefor, an operatinghandle on the front of the cover, a lever on the inside of said coverhaving one end connected to said handle, a switch unit in the boxincluding movable switch members, a

. yoke for actuating said movable switch members and a rocking platehaving a link connectionvwith `said yoke, said plate having a slotVadapted to receive the free end of said leverfor moving the plate whenthe cover is closed. 'j

7. An enclosed switch including "a box, a cover therefor, an operatinghandle on the front of the cover, a lever on the inside of said coverhaving one end connected to said handle, two switch units in the box,each unit including movable switch members and a yoke for actuating saidmovable switch members, and a rocking plate having a separate lostmotion link connection with each of said yoke members and having aslotted connection with said lever when the cover isA closed, said platewhen rocked'to either side of its center being adapted to move either ofsaid yokes and its respective movable switch members to on position, theother yoke member remaining stationary.

8. In an electric switch. a pivoted crank shaft, a reciprocable switchmember having a slotted connection with said crank shaft, a springpressed throwing member having a slotted connection with said crankshaft, a support for said throwing member at the end opposite saidslotted connection, a rocking plate, and a link having a slottedconnection with said shaft and hinged to said plate so that when therocking plate is moved from a neutral position with the circuit of theswitch open toward a closed circuit position ofl the switch the crankand the link move the switch member toward the closed circuit positionagainst the spring bias of the `throwing member.

9. A- switch having two switch units, each unit including movable switchmembers normallyv 10. In an electric switch, two pivoted crank shafts, aswitch member separately connected to each Acrank shaft to be movedthereby, a spring pressed throwing member for each shaft, a singlerocking member, and links having separate slotted connections with eachof said shafts and hinged to said rocking member'so that when therocking member is moved from a neutral position with the circuit of theswitch open, to a closed circuit position of the switch, one crank andits throwing member hold one switch member in the ofP position while theother crank is moved by its link to place its switch member in the onposition.

BENJAMINE. GETCHELL.

